TRUNCATE

Delete all of the rows from one or more tables without doing table scans.

TRUNCATE [ TABLE ] name [ * ] [, ... ]
    [ CASCADE | RESTRICT ]

This is a faster operation than an unqualified DELETE operation. The results are the same. Use the CASCADE option to automatically truncate tables that have foreign-key references to the named tables.

Rollback is supported for TRUNCATE operations.

For example, truncate three tables:
premdb=# truncate table hometeam, awayteam, team;
TRUNCATE TABLE